Gabapentin may ease symptoms of marijuana withdrawal

Need help getting the marijuana monkey off your back? The widely prescribed anticonvulsant drug gabapentin might be just the ticket, if preliminary clinical trials at the Scripps Research Institute are confirmed. A 12-week trial in 50 marijuana users who wanted to quit showed that gabapentin (sold under a variety of brand names, including Neurontin) reduced withdrawal symptoms and that those who took the drug were more likely to stop smoking maryjane altogether.

Many people view marijuana as a relatively benign substance; others regard it as a gateway to use of more powerful recreational drugs. Is it addictive? Studies show that 16% to 25% of admissions to treatment programs for substance abuse involve people with primary marijuana dependence.

For heavy users, trying to quit can produce a host of withdrawal symptoms, including drug craving, sleep disturbances, anxiety, irritability and dysphoria -- all of which can prompt the user to go back to smoking pot. A 2008 study by Dr. George Koob of Scripps found that gabapentin could quiet such withdrawal activity in alcohol-addicted rats. That led Dr. Barbara J. Mason of Scripps to initiate a clinical trial of the drug for marijuana abuse.

The team ran ads in a local newspaper and online headlined: "Smoking too much pot? We want to help you stop." The team needed 50 volunteers; it received more than 700 inquiries.

Half of the 50 recruits were given 1,200 milligrams of gabapentin a day and ther other half were given a placebo. All subjects also received counseling about quitting.

The team reported in the online version of the journal Neuropsychopharmacology that self-reports and urine testing indicted that about twice as many of the gabapentin subjects had no new cannabis use during the study. During the last four weeks of the study, all the gabapentin users who completed the study stayed abstinent. The drug also clearly reduced symptoms such as sleep disturbances, drug cravings and dysphoria. It may also have increased mental acuity. Seven of the gabapentin users and 10 who received the placebo sat for tests of attention, impulse-control and other brain functions before the start of the trial and at Week 4. The placebo patients tended to score lower on all the tests at Week 4, while those receiving gabapentin scored higher, indicating better mental functioning.

The team is now conducting a larger trial of gabapentin sponsored by the National Institute on Drug Abuse and the National Institutes of Health. Smokers interested in participating may contact them at (858) 784-7867.